Socket Sizes In Order From Smallest To Largest
Quick answer: socket sizes are usually organized by drive size, then by measurement system. The most common drive sizes are 1/4-inch, 3/8-inch, and 1/2-inch. Small metric sockets commonly start around 4 mm, small SAE sockets commonly start around 5/32 inch, and larger mechanic sets often run up to 32 mm or 1-1/2 inch.
How Socket Sizes Are Organized
Socket sizing can be confusing because three things are mixed together: drive size, socket opening size, and measurement standard. The drive size is the square hole that attaches to the ratchet. The socket opening is the part that fits over the nut or bolt. The measurement standard is either metric or SAE/inch.
[gs_table id=”9310″]Metric Socket Sizes Chart
This chart lists common metric socket sizes from smallest to largest. Not every set includes every size, and specialty sizes may exist outside this list.
[gs_table id=”9312″]SAE Socket Sizes Chart
SAE sockets use fractional inch sizes. The list below runs from smaller fractional sockets to larger sockets commonly found in mechanic sets.
[gs_table id=”9319″]SAE To Metric Socket Conversion Chart
Use conversions as a guide, not as permission to use the wrong socket. A close metric size can round a fastener if the fit is loose, especially on rusty, soft, or high-torque hardware.
[gs_table id=”9321″]Which Socket Set Sizes Matter Most?
For a home garage, a useful starting point is a 1/4-inch metric set from 4 mm to 14 mm, a 3/8-inch metric set from 8 mm to 19 mm, and a 1/2-inch set that covers 17 mm, 19 mm, 21 mm, 22 mm, and larger sizes for wheels and suspension. If you work on older American equipment, add SAE sockets from 1/4 inch through 1 inch.
Common Socket Size Mistakes
- Mixing drive size with socket size: a 10 mm socket can come in 1/4-inch drive, 3/8-inch drive, or even 1/2-inch drive.
- Using chrome sockets on impact tools: use impact-rated sockets with impact wrenches.
- Forcing a close conversion: the closest metric socket is not always safe on an SAE fastener.
- Ignoring 6-point vs 12-point: 6-point sockets grip better on stubborn or rounded fasteners.
- Assuming every kit is complete: many kits skip sizes such as 16 mm, 18 mm, 20 mm, or 23 mm.
Related GarageSanctum Guides
If you are building out a tool drawer, also see our American wrench size chart, bolt chart with wrench size, best socket sets for the money, and best socket organizers.
Source Notes
Conversion values use the standard inch-to-millimeter relationship of 1 inch = 25.4 mm. Socket set ranges vary by manufacturer, so treat the charts as a practical reference rather than a guarantee that every retail kit includes every listed size.
